source file: m1400.txt Date: Wed, 29 Apr 1998 21:44:16 -0500 Subject: Re: JI Tuning Resolution From: "jloffink" > From: "Paul H. Erlich" > For a delay time just 1/2000 of a second longer, you get > destructive interference, or no energy at that frequency. > > Now if the onset times are controlled really accurately by MIDI, and > let's say a 90-degree phase shift is chosen so that the energy at 1000Hz > is twice that from one instrument, then you're doing okay, right? > ..otherwise known as phase cancellation. A MIDI note on message is 20 bits at 31250 Kbaud, so the best case timing between each consecutive note on the same MIDI cable is 640 us. Actual results would be much worse due to processing time by your sequencer and especially your MIDI synthesizer. Keyboard's MIDI Timing Slop tests in the July 1996 issue showed average timing irregularities of 0.29 to 1.95 ms for a single MIDI note and 0.30 to 3.36 ms for 1 voice alternating with 12 voices, except the Roland XP-10 which showed 19.14 ms of timing variation. Instruments tested included some of the common microtonal ones: Ensoniq MR-Rack, Korg M1 and Trinity, Kurzweil K2500RS, Roland XP-50 and Yamaha TX802. I wouldn't recommend MIDI for anyone needing Rayna/Kyma/CSOUND type resolution. John Loffink jloffink@pdq.net